Method and apparatus for scoring and flattening tubes

ABSTRACT

TUBES COMPOSED OF FIBER MATERIAL ARE PASSED SEQUENTIALLY THROUGH A SCORING APPARATUS WHEREIN LONGITUDINALLY EXTENDING SCORE LINES ARE FORMED IN THE TUBE, AND A COMPRESSION ZONE WHEREIN THE SCORED TUBES ARE FLATTENED.

Oct. 5,, 1971 E EIAL 3,610,115

METHOD AND APPARATUS FON SCORING AND FLATTENING TUBES Filed July 18, 1969 3 Sheets-Sheet 1 INVENTORS E. E. ROSE F. F. RICHARDS A T TORNEVS Oct. 5, 1971 5, 055 ETIAL 3,610,115

METHOD AND APPARATUS FOR SCORING AND FLATTENING TUBES Filed July 18, 1969 3 Sheets-Sheet 2 FIG.

INVENTORS E. E. ROSE F. P. RICHARDS A T TORNE VS OCLS, 1971 RQSE EI'AL 3,610,115

METHOD AND APPARATUS FOR SCORING AND FLATTENING TUBES Filed July 18, 1969 3 Sheets-Sheet S INVENTORS E.E.ROSE BY F. P. RICHARDS A T TORNEVS United States Patent Office 3,610,115 Patented Oct. 5, 1971 3,610,115 METHOD AND APPARATUS FOR SCORING AND FLATTENING TUBES Earl E. Rose and Frank P. Richards, Kansas City, Mo., assiguors to Phillips Petroleum Company Filed July 18, 1969, Ser. No. 843,157 Int. Cl. B31c 3/04; B31b 1 88, 43/00 US. Cl. 93-80 2 Claims ABSTRACT OF THE DISCLOSURE Tubes composed of fiber material are passed sequentially through a scoring apparatus wherein longitudinally extending score lines are formed in the tube, and a compression zone wherein the scored tubes are flattened.

This invention relates to fiber containers. In one aspect it relates to a novel method and apparatus for collapsing fiber containers and placing them in a condition for transit and/ or storage.

Fiber containers are made in a variety of constructions, principal of which is the convolute wound, lap seam, and spiral wound. All constructions include a tubular body composed of plies of fiber material and separate end closures. The fiber container is rapidly supplanting metal containers in many packaging areas such as food, coffee, motor oil, and the like. One advantage offered by the fiber container, particularly for containers having a volume capacity of two or more gallons, is its ability to be collapsed to a flattened condition for transit and/ or storage. At the situs of use, the container can be assembled by expanding the body and inserting the end closures. In order to collapse the tubular body of the container, longitudinally extending scores are formed in the container body so that when the body is collapsed to the flattened condition the wall will break along the weakened lines provided by the scores thereby preventing wall cracking. The packaging line can conventionally be mechanized so that the tubular container bodies are automatically formed and flattened in a continuous process. This conventional process involves first continuously forming the bodies on the winding mandrel, cutting them to length and then feeding them one at a time sideways in a more or less random fashion through a scoring zone and then a compression zone wherein the container is flattened. Since the attitude of the container is not controlled when it enters the compression zone, there are no means for placing the score lines in proper alignment with the compression forces. Consequently, many score lines are circumferentially spaced about the container so that at least two diametrically positioned score lines will be in proper alignment with the compression forces as it passes through the compression zone. Thus, it will be appreciated that the majority of these score lines serve no practical function and, furthermore, the equipment required to provide the surplus score lines unduly complicates the system. More importantly, however, the surplus score lines adversely affect the column strength of the container. For containers used to package liquids, the column strength is of paramount importance. For example, when two gallon containers containing ice cream melt are stacked in a refrigerator, it has been found that the bottom containers fail in compression. The failure is due to the weakened condition of the container resulting from the large number of longitudinally extending score lines.

The purpose of the present invention is to provide a collapsible fiber container having superior column strength thereby enabling the container to withstand the compressive forces when stacked one on another.

The present invention contemplates maintaining the tubular container body under control throughout the scoring and flattening phases of the operation. More specifically, the attitude of the tubular body emerging from the scoring assembly is maintained in a fixed attitude as it passes through the compression zone. By maintaining its attitude, the tubular body requires only two diametrically positioned score lines, which determine the point at which the tubular body breaks when flattened. For thin-walled containers, two score lines are sufficient, but for thick-walled containers additional score lines located intermediate the diametric score lines may be necessary to prevent wall cracking of the semicircular wall surfaces being flattened. For convenience of illustration, the dia metric score lines will be referred to as the primary score lines and the additional score lines as the secondary score lines. The number, location and configuration of the secondary score lines will depend to a large extent upon the composition and dimensions of the tubular bodies. It should be observed that the sole function of the secondary score lines is to determine the point at which the semicircular halves break in moving to the flattened condition.

The present invention contemplates the continuous process of forming an elongate tube by wrapping webs of fiber material around a winding mandrel; cutting the tube at longitudinally spaced intervals thereby forming container bodies, and while maintaining a fixed attitude on the body passing it sequentially through a scoring apparatus wherein at least two diametrically located longitudinally extending scores are formed therein and then flattening the body by pressing the semicircular portions on either side of the score lines inwardly.

The apparatus for constructing the container body is conventional and can be according to the techniques known as convolution winding, lap seam, or spiral wind- The novel scoring and flattening apparatus comprises at least two opposed scoring rollers engageable with op posite sides of the container wall at diametric points, and opposed compression means positioned within one container length from the scoring apparatus. Thus, it will be appreciated that the container body is maintained in a fixed attitude as it passes sequentially through the scoring apparatus and the flattening apparatus.

In summary, then, an object of this invention is to provide a method and apparatus for scoring and flattening fiber containers. Another object is to provide an in-line process wherein the fiber container is first scored and then collapsed in a predetermined attitude. A further object is to provide a method and apparatus wherein the container is flattened as it passes endwise through a compression zone. These and other objects will become apparent to those skilled in the art from the following disclosure taken in conjunction with the attached drawings in which:

FIG. 1 is a diagrammatic view illustrating the in-line system comprising a spiral winding apparatus, a cutting apparatus, a scoring apparatus, and a flattening apparatus;

FIG. 2 is an enlarged fragmentary front elevational view showing details of the scoring apparatus;

FIG. 3 is a sectional view of FIG. 2 taken generally along the cutting plane indicated by line 3-3 thereof; and

FIGS. 4 and 5 are transverse sectional views of the scored tubular body in the expanded and the flattened conditions, respectively.

As shown in FIG. 1 the in-line equipment for forming collapsed container bodies includes an apparatus for forming a round elongate tube, comprising a cutting apparatus 11 for cutting the tube at longitudinal intervals forming cylindrical open-ended container bodies, a scoring apparatus 12 for forming longitudinally extending scores in the container bodies, and a flattening apparatus 13 for collapsing the cylindrical body to a flattened condition for transit and/ or storage.

The present invention is described in connection with a machine for manufacturing a container constructed by the spiral wound technique, but it should be understood that the principles exemplified therein are applicable to other container constructions, the only requirement being that the container be wound on a mandrel and that the system be adapted to an in-line process contemplated by the present invention.

The spiral wound body is manufactured by pulling multiple webs, two shown in FIG. 1 as 14 and 15, of material over a winding mandrel 16. The webs 14 and 15 can be composed of paperboard or plies of foil, plastic films or specially treated paper liners such as the type commonly used in composite cans. An adhesive is applied to the webs to bond them together as they are wrapped in overlying relation on the mandrel 16 forming an elongate tube shown generally as 18. An endless belt 19 looped around tube 18 and trained about spaced-apart, driven pulleys 20 and 21 provides the means for turning the tube 18 and advancing it along the mandrel 16. Thus, as the tube is continuously rotatably advanced along the mandrel 16, the webs 14 and 15 are spirally wound thereon and bonded together thereby continuously forming the container walls.

As the tube 18 is advanced along the mandrel 16, a leading portion thereof passes adjacent the cutting apparatus 11 comprising a pair of spaced cutting rollers 22 and 23 keyed to shaft 24. The assembly 11 can be movably mounted in relation to the mandrel 16 and movable in timed relation with the advancing tube 18 so that when the cutters are placed in the cutting position the tube 18 is circumferentially cut at longitudinal intervals. The spacing of the cutting rollers 22 and 23 is equal to the container body length. Thus, the cutting assembly 11 operates to sever individual container bodies shown as 25 from the elongate tube 18. The severed body 25 is pushed forwardly along the mandrel 16 by the advancing tube 18 until the leading edge of body 25 contacts the periphery of friction rollers 26 and 27. The peripheral speed of the rollers 26 and 27 is greater than the rate of advancement of the tube 18 so that body 25 is pulled away from the tube 18 and forced into the scoring apparatus 12.

As shown in FIGS. 2 and 3, the scoring apparatus 12 includes four sets of rollers 28, 29, 30 and 31, each set comprising a driven roller 32 and a backup roller 33. In this embodiment the driven and backup rollers of one set, e.g., 28, are identical tothose of the other sets, e.g., 29-31. Therefore, the same character references (32 and 33) identify respectively the driven rollers and backup rollers for each set 2 8-31. The backup rollers 33 of sets 28-31 are free-wheelingly mounted on a structure shown generally as 34 which includes a shaft 35 mounted on the forward end of mandrel 16 (see FIG. 3) and a cross member 36 secured to the forward end of shaft 35. The cross member 36 journally supports the backup rollers 33. The backup rollers 33 each have a circumferentially extending groove 37 the width of which determines the width of the score formed in the body 25. The backup rollers 33 are arranged so that their outer peripheries engage the interior surface of the body 25 passing through the scoring apparatus 12.

The driven rollers 32 are each mounted on a lever 39 which in turn is pivotally mounted on a frame 40. Since the driven rollers 32 of each of the sets 28-31 and its associated lever 39 are identical in structure, only one set will be described in detail, with like reference characters being assigned to corresponding parts of the other sets. The frame 40 is in the form of a plate transversely disposed across the path of the oncoming container bodies 25. The frame 40 has formed therein a square opening 41 which is aligned with the mandrel 16. Drive means comprising a main sprocket and chain assembly shown generally as 42 (FIG. 1), bevel gear boxes 43 (FIG. 2), shafts 44 (FIG. 2), and chain drive 45 (FIG. 3) transmits power from a motor 46 (FIG. 1) to the separate driven rollers 32. Each lever 39 is in the form of a dog leg having an upright portion 47 and an angularly disposed portion 48 (FIG. 3). The outer end of portion 48 is bifurcated, the roller 32 being received between the forks and keyed to a shaft 49 journally mounted to the lever 39.

Each driven roller 32 is arranged in confronting relation with a corresponding backup roller 33 and is provided with a circumferential rib 50. The width of the rib 50 is slightly less than the width of groove 37 so that a peripheral portion of the former is received in a peripheral portion of the latter. The shoulders on either side of the groove 37 and rib 50 of rollers 33 and 32, respectively, can be knurled in order to increase the gripping ability at the nip between the two. The scoring roller sets 28-31 are disposed 90 degrees apart so that the container body 25 is engaged at four circumferentially and equally spaced points. Thus, as the container body 25 enters the scoring apparatus, the driven rollers 32 in combination with the backup rollers 33 grip the container body advancing it therethrough. As the container body is advanced therethrough, the action of the ribs 50 presses wall portions of body 25 into the grooves 37 forming longitudinal score lines. The amount of pressure at the nip of each of the scoring roller sets will depend upon the thickness of the body Wall and the composition of the body.

In order that the scoring apparatus 12 can accommodate a variety of container bodies, both as to wall thickness and as to body composition, means are provided for controlling the pressure at a nip of the scoring roller sets 28-31.

As best seen in FIG. 3, the lever 39 has formed therein a tab 51 journaled to shaft 44. The tab provides a pivot axis for the lever 39 and roller 32 carried thereby. The end of portion 47 extends through a slotted bar 52 secured to frame 40. Bolted to the forward side of frame 40 is an air cylinder 53. Cylinder 53- has a piston rod 54 projecting through aperture 55 and engageable with the edge of upright portion 47 of lever 39. Extension of piston rod 54 pivots lever 39 about the axis provided by tab 51 and moves roller 32 toward roller 33 thereby increasing the pressure on the tube wall disposed therebetween. The pivotal movement of lever 39 is limited to the length of the slot in bars 52. Set screw 56- provides means for adjusting the slot length.

The flattening apparatus 13 includes a pair of belt conveyors 57 and 58. The conveyor 58 has an endless belt 59 trained about spaced pulleys 60 and 61. Similarly, conveyors 57 and 58. The conveyor 58 has an endless belt pulleys 63 and 64. Pulleys 61 and 64 are counterrotative- 1y driven providing counterorbital movement for their associated belts. The endless belts 59 and 62 have runs 65 and 66 arranged in confronting relation and in combination define a compression zone 67. Backup frames 68 and 69 for runs 65 and 66, respectively, maintain the proper spacing for the belts 59 and 62 through the compression zone 67. The compression zone 67 has an inlet 70 the height of which is slightly greater than the diameter of the container body 25. The runs 65 and 66 converge from the compression zone from the inlet 70 continuously to its outlet 71. The location of the compression zone inlet '70 is less than one body length from the nip of the scoring roller sets 28-31 so that the tubular body emerging from the scoring apparatus 12 comes under the force of the flattening apparatus 13 while still under the control of the scoring apparatus 12. Thus, the body 25 is maintained in a fixed attitude throughout the flattening steps of the process, and in passing through compression zone 67 the body 25 is crushed gradually from the fully cylindrical condition as shown in FIG. 4 to the fully flattened condition as shown in FIG. 5.

As indicated earlier, the scoring apparatus 12 forms primary and secondary longitudinally extending scores in the container body 25. In this embodiment, the scoring roller sets 29 and 31 form the primary scores and sets 28 and 30 form the secondary sets. It should be noted that for thin-walled flexible containers only the primary scoring sets 29 and 31 are required. The terms primary and secondary are used merely to indicate the different functions of the scores. For example, as shown in FIG. 4, the primary scoring sets 29 and 31 form longitudinally extending scores or depressions 72 and 73, respectively. Each score provides flexure joints 74 and 75 about which the semicircular surfaces on either side of the scores 72 and 73 can bend. The scores or depressions 76 and 77 formed by the scoring sets 28 and 30 also permit flexing of the wall but flexing is in the opposite direction as is evident in FIG. 5. The depressions provided by the secondary scores permit bending of the wall without cracking. Primary scores 72 and 73 lie in a plane which is normal to the compression force of the compression zone 67. When the container body 25 emerges from the scoring apparatus 12 and enters the compression zone 67 the opposed belt runs 65 and 66 engage the leading edge of the body 25 at diametric points approximately located at the secondary cores 76 and 77. Drive pulleys 61 and 64 can propel the belts 59 and 62 at a greater rate or about the same rate as the peripheral velocity of the driven rollers 32. As the container body passes through the continuously diminishing compression zone 67, the compressive forces applied at the diametric points press the container to the flattened condition shown in FIG. 5.

In summary, then, the process according to this invention comprises the steps of forming a fiber container body, passing the body in a fixed attitude through a scoring apparatus where at least two diametrically positioned longitudinally extending score lines are formed coextensive with the length of the body, and while in said fixed attitude passing said scored body through a compression zone wherein compressive forces are applied in a direction transverse to the plane defined by said score lines thereby causing said body to be substantially flattened.

As indicated earlier the function of the primary score lines 72, 73 and secondary score lines 76, 77 are different. Consequently, the configuration of the primary and secondary lines can "be different to effectively perform their respective functions. For example, it may be desirable to deform the secondary score lines 76, 77 less than the primary score lines 72, 73 since the sole function of the secondary score lines is to localize bending thereby preventing cracking of the container wall. The means for controlling the pressure at the nip of the scoring roller sets 2831 can be selectively operated in order to provide the difference in the primary and secondary score lines. It should also be observed that the configuration of the score rollers 32, 33 can be modified to provide a wide variety of score line configurations. For example, under certain conditions it may be desirable to intermittently score the container wall or it may be desirable to intermittently oifer means for controlling the operation of the scoring means to suit the conditions of a particular container composition and wall thickness.

While this preferred embodiment has been described in particular detail, it should be emphasized that variations and modifications may be made therein Without departing from the scope and spirit of the invention as set forth in the appended claims.

We claim:

1. In an in-line container forming machine including means for spirally winding multiple webs of fiber material on a winding mandrel to form an elongate tube thereon, means for cutting said tube at longitudinal intervals forming cylindrical container bodies, and scoring means for forming longitudinally extending score lines in said bodies,

the improvement wherein said scoring means comprises: an outer frame having an opening formed therein, said opening being in axial alignment with said mandrel; a plurality of scoring rollers mounted on said frame and extending inwardly of said opening placing peripheral portions of said rollers in position to engage the outer surface of said bodies passing axially through said openings, at least two of said rollers being arranged to engage said body at diametric points; a plurality of backup rollers supported by said mandrel and arranged in confronting and companion relation with said scoring rollers, each of said backup rollers adapted to engage the internal surface of said bodies passing through said opening, each of said scoring rollers and said companion backup rollers having their peripheries disposed in confronting relation to respectively engage the outer and inner surfaces of said body wall passing therebetween and being complementary-shaped for longitudinally deforming the wall of said body passing therebetween; a plurality of levers, each having a scoring roller journally supported at one end thereof with each of said levers being pivotally mounted on said frame for moving each of said scoring rollers relative to said companion backup means for varying the spacing and the press force on the body wall disposed therebetween; means for forcefully driving each of said bodies axially through said score means; and means for rotationally driving said scoring rollers whereby a plurality of longitudinally extending scores are formed on said body.

2. In an in-line container forming machine including means for spirally winding multiple webs of fiber material on a winding mandrel to form an elongate tube thereon, means for cutting said tube at longitudinal intervals forming cylindrical container bodies, and scoring means for forming longitudinally extending score lines in said bodies, the improvement wherein said scoring means comprises: an outer frame having an opening formed therein, said opening being in axial alignment with said mandrel; a plurality of scoring rollers mounted on said frame and extending inwardly of said opening placing peripheral portions of said rollers in position to engage the outer surface of said bodies passing axially through said openings, at least two of said rollers being arranged to engage said body at diametric points; backup means supported by said mandrel and arranged in confronting and companion relation with said scoring rollers, said backup means adapted to engage the internal surface of said bodies passing through said opening, each of said scoring rollers and said companion backup means having complementary-shaped portions for longitudinally deforming the Wall of said body passing therebetween; means for moving each of said scoring rollers relative to said companion backup means for varying the spacing therebetween; means for forcefully driving each of said bodies axially through said score means whereby a plurality of longitudinally extending scores are formed therein; a body flattening apparatus disposed in-line with said scoring means, said flattening apparatus including force means for applying a press force on the outer surface of said body in a direction transverse to the plane defined by said diametric longitudinally extending score lines, and means for passing said body from said scoring means to said flattening apparatus with said body flattening apparatus being mounted less than one body length from said scoring means for passing said body in a fixed attitude so that the relationship of the direction of said force in said plane is maintained and said force of said flattening apparatus becomes operative upon a leading portion of said body while the force of said scoring means is operative upon a trailing portion of said body; and other pairs of scoring rollers in addition to said diametrically arranged scoring rollers, said other pairs of scoring rollers being of a number in the range of 1-2 pairs with each roller of a pair being circumferentially spaced between said diametric scoring rollers, diametrically positioned relative one to the other, and operative to form longitudinally extending scores in said body for locating 7 the line at which the body Wall breaks between said diametrically arranged score lines in moving from the circular to the flattened configuration.

References Cited UNITED STATES PATENTS Gale 93-94 (PS) Perusse 93-80 Onderdonk 93-58.1 X

Harbeck 93-94 (PX) La Bombard 93-80 Lysobey- 9358.2 X

8 Cvacho 93-80 Richter 1 93 94 (PX) Sheeran 93-58.1 Geisler 93-94 X Sloan 93-58.1 X

FOREIGN PATENTS Germany 93-5 8.1

10 WAYNE A. MORSE, IR., Primary Examiner US. Cl. XR.

93-1 G, 8 W, 58.1, 58.2, 58 ST 

